Ageratum, also called floss flower, is a compact annual prized for its fluffy, powder-puff clusters of blue, purple, pink, or white blooms that last from early summer straight through frost.
Native to Central America and Mexico, Ageratum has become a garden-border staple worldwide thanks to its long bloom season, low maintenance, and reliable color even in less-than-ideal soil. Its fuzzy, thread-like flower heads are its most recognizable feature, giving the plant its "floss flower" nickname.
Ageratum symbolizes trust and lasting affection, and its old-fashioned name — "ageratos," Greek for "un-aging" — nods to how long its blooms hold their color before fading.
Ageratum thrives in full sun to partial shade and tolerates average, well-draining soil without much fuss. Start seeds indoors six to eight weeks before the last frost, or set out nursery transplants once frost danger has passed. Deadheading spent blooms keeps plants tidy and encourages continuous flowering through the season, and a light pinch-back mid-summer helps prevent legginess in taller varieties.
Certain Ageratum species have a history of use in traditional medicine across Central America and Africa, where preparations from the leaves were used topically for wound care and as an insect repellent.
